Releasable latch for doors



Dec. 27, 1966 E. PASCUCCI ETAL 3,

RELEASABLE LATCH FOR DOORS Filed March 24, 1964 5 Sheets-$heet 1 INVENTORS .EeA/a'r PA .rcwa/ BY jJ/la PflJCUcC/ Dec. 27, 1966 E. PASCUCC! ETAL 3,

RELEASABLE LATCH FOR DOORS 5 Sheets-Sheet 2 Filed March 24, 1964 INVENTORS [PA 5 r PAscz/cc/ Tu/la Fflsc ucc/ 1966 E. PASCUCCI ETAL 3,

RELEASABLE LATCH FOR DOORS 3 Sheets-Sheet 5 Filed March 24, 1964 lllllwli IN A e/var ,4

United States Patent ()fiice 3,294,432 Patented Dec. 27, 1956 3,294,432 RELEASAIELE LATQH FOR DOORS Ernest Pascucci and Julio Pascncci, Meriden, Conn., assignors to The Miller (Jornpany, Meriden, Conn, a corporation of Connecticut Filed Mar. 24, I964, er. No. 354,406 6 Claims. (Cl. 292122) This invention relates to releasable latches and more specifically to a novel and improved latch particularly useful for lighting fixture closures to securely latch a door in the closed position and which will automatically release the door for movement to the open position upon displacement of the door inwardly of the lighting fixture and then release.

Releasable door latches have heretofore been proposed though known latches have involved the use of relatively complicated and expensive constructions which required a substantial amount of space for installation. This invention provides an improved releasable latch that is positive in its action, small and compact, and is composed of a plurality of parts which can be manufactured, assembled and replaced at relatively low cost.

Another object of the invention resides in the provision of a novel and improved latch particularly adaptable for use with lighting fixture closures that is readily and easily installed and maintained.

A still further object of the invention resides in the provision of a novel and improved releasable latch for doors and other similar purposes.

The above and other objects and advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the drawings:

FIGURE 1 is a side elevation in partial section of a lighting fixture embodying a door latch in accordance with the invention.

FIGURE 2 is an exploded perspective view of the portion of the latch secured to the lighting fixture.

FIGURE 3 is an exploded fragmentary view of the lighting fixture closure with the cooperating portion of the latch carried by the closure.

FIGURE 4 is a cross-sectional view of a lighting fixture and closure with the latch in accordance with the invention shown in elevation.

FIGURE 5 is a top plan view of the latch shown in FIGURE 4.

FIGURE 6 is a cross-sectional view of FIGURE 4 taken along the line 66 thereof.

FIGURE 7 illustrates the assembly of that portion of the latch carried by the lighting fixture body.

FIGURE 8 is a partially diagrammatic illustration showing the latching elements prior to latching engagement.

FIGURE 8a is a cross-sectional view of FIGURE 8 taken along the line aa thereof.

FIGURE 9 is a partially diagrammatic illustration showing the latching elements engaged but not yet latched.

FIGURE 10 is a partially diagrammatic illustration showing the latching elements in latched position.

FIGURE 11 is a partially diagrammatic illustration showing the latching elements in released position.

FIGURE 11a is a cross-sectional view of FIGURE 11 taken along the line a-a thereof.

While the latch in accordance with the invention is particularly useful for lighting fixture closures wherein the fixture is mounted in a ceiling or sloped wall in which gravity will operate to move the closure to an open position upon release of the latch, it is to be understood that the latch is equally applicable for any type of door or closure disposed in a vertical plane and wherein suitable spring means would be utilized to urge the door outwardly in much the same manner as gravity would react on a door mounted in a horizontal plane.

Referring now to the drawings and more specifically to FIGURE 1, the lighting fixture is generally denoted by the numeral 10 and comprises a peripheral wall 11 having a closure receiving channel 12 spaced inwardly from the wall 11. The channel 12 further carries a reflector 13 in which a suitable source of illumination, such as an incandescent lamp, may be disposed. The front of the fixture includes a closure 14 having a peripheral frame 15 and a light transmitting element 16 carried by the frame. The light transmitting element may be in the form of a grid or may be translucent or transparent glass, plastic, or the like. The closure 14 is hinged at 17 to the closure receiving channel 12 so that it may move outwardly as shown generally by the dotted line position. Since the fixture is mounted in a horizontal plane, gravity will move the door to the open position upon release of the latching means illustrated generally by the numeral 18. Upon movement of the closure 14 to the closed position, the latch will automatically engage the closure and hold it in the closed position. Upon moving the closure inwardly of the fixture, the latch will disengage the closure and permit the latter to move to the open position. The latch and its cooperation with the closure or door is shown more clearly in FIGURES 2 through 7.

The closure receiving frame 12 in the illustrated embodiment of the invention has a vertical wall 19, a lower horizontal flange 20, and an upper inwardly extending horizontal flange 21. The flange 21 has an essentially rectangular opening 22 which includes a small tab 22 extend ing inwardly from one edge thereof. The latch portion attached to the frame 12 comprises essentially three elements, namely, a U-shaped supporting bracket 23, an actuator arm 24, and a coil spring 25. The U-shaped supporting bracket 23 is preferably formed of a spring material, such as steel, brass, or the like, and has a pair of inclined side walls 26 and 27 and a top wall 28. The side walls 26 and 27 are provided with flanges 29 extending outwardly from the sides thereof and terminating at points spaced from the lower edges thereof. The lower edges of the side walls 26 and 27 are provided with outwardly extending flanges 30 and 31, the latter having a central cutout portion 32. The U-shaped bracket 23 is inserted in the opening 22 by springing the side walls 26 and 27 inwardly until the flanges 30 and 31 clear the ends of the slot 22. T e bracket is aligned with the slot so that the tab 22' enters the cutout portion 32 of the bracket. The flanges 30 and 31 underlie the edges of the slot 22 and the bottom edges of the side flanges 29 engage the top surface of the edges of slot 22. In this way, the bracket 23 is firmly held in position without the need for screws, rivets, or other suitable fastening means. If desired, side plates 12a and 121) may be affixed to the edges of the opening 22 as shown in FIGURES 4 and 5 to further stabilize the bracket 23.

The top wall 28 is provided with an opening 33 which includes a long slotted portion 34, a shorter slotted portion 35 and a narrow portion 36 interconnecting the slotted portions 34 and 35. This configuration facilitates engagement of the operating arm 24 with the frame for supporting the operating arm in the desired position. Moreover, by reason of this improved arrangement, should the operating arm 24 be damaged in any way, it can be readily and easily replaced without the need for special tools or even removal of the fixture from its installed position.

The operating arm 24 has a shank 37 of a width corresponding to the length of the slotted portion 34 of the opening 33 in the frame 23 so that it will readily slide through that slotted portion. A boss 38 on the top end of the shank 37 permits the actuator arm to be inserted in the slotted portion 34 in only one position. The shank 37 has a reduced section 39 spaced from the top thereof, and the width of the reduced section 39 corresponds to the length of the slotted portion 35 of the frame 23. Immediately below the portion 39 on the shank 37 is a further reduced section 40 having a width which corresponds to the portion 36 of the opening 33. The lower portion of the operating arm 24 has a transverse portion 41 of a width substantially greater than that of the shank, a depending arm 42 shaped in the form of a partial hook and the lower end includes an outwardly extending tab 43 which comprises the actual latching element. The spring 25 which cooperates with the operating arm 24 has a diameter slightly larger than the shank 37 and the lower end of the spring rests on the shoulders formed by the transverse member 41. The upper end of the spring is formed with a narrow slotted portion 25 which closely engages the shank 37 and will permit the boss 38 to pass therethrough.

Assembly of the operator arm and spring to the bracket 23 is accomplished by placing the spring 25 over the end of the operator arm 24. The operator arm is then pushed upwardly through the slotted portion 34 until the narrowed section 40 is in alignment with the portion 36 of the opening 33. The arm is then moved to the right as shown in FIGURES 2 and 7 until the reduced section 39 of the shank is in line with the slotted portion 35. The operator arm is then released and the spring 25 will urge it downwardly bringing the reduced section 39 into engagement with the slotted portion 35. The shoulders immediately above the reduced section 39 limit the downward motion and thus the operator arm is locked in place in the slotted portion 35. At the same time, sufiicient clearance is provided to permit the operator arm to be moved through an angle as will be described in connection with FIG- URES 8 through 11.

The door frame carries a latching cam 44 which cooperates with the latching tab 43 to hold the door in the closed position. The latching cam is formed of a flat piece of material having an opening 45 for attaching it to the door frame 15 by a rivet 46 or other suitable fastening means. By spacing the opening 45 from the bottom edge 44' of the plate 44 so that the edge 44 rests against the flange 15' of the door frame 15, a single rivet will fix the latching cam in the desired position on the door frame.

The upper edge 47 of the latching cam is inclined and includes an outwardly extending tab 48 and a cam 49 having an inclined surface 50 on the top side thereof and a curved bottom edge 51. The edges 50 and 51 terminate in an elongated finger 52 which is spaced vertically from the top edge of the tab 48 a distance which is narrower than the height of latching tab 43 on the operator arm 24. As will be shown, this arrangement insures a positive lock each time the door is closed since the latching tab 43, when closing the door, slides over the end of the finger 52 and engages the tab 48 until the door is released, whereupon the latching tab is disengaged from the tab 48 and moves inwardly until it strikes a stop 53 as may be observed in FIGURE 6. Stop 53' forms part of a plate 53 which offsets the cam 49 from the plane of the plate 44 as may be observed more clearly in FIGURE 3. To open the door, the door is slightly depressed so that the latching tab 43 clears the stop 53, in which case it moves to a vertical position and then release of the door causes the latching tab 43 to ride on the inclined surface 50 and permits the door to open. As will be shown, it is important that a vertical line intersecting the latching tab 43 when the actuator arm is in a normal center position falls to the left of the stop 53' as viewed in FIGURE 3 and to the right of the cam surface 50. This relationship will be more readily understood from the following de- 4 scription of FIGURES 8 through 11 showing the actual operation of the latch in accordance with the invention.

FIGURE 8 shows the actuator arm 24 in the normal position with reference to the bracket 23. As the door is closed, the cam latch 44 moves from the lower dotted line position upwardly to the full line position where the top cam surface 50 engages the latching tab 43. Further movement of the cam latch upwardly to the upper dotted line position displaces the operating arm 24 to the right, as viewed in FIGURE 8, until it clears the end of the finger 52. The horizontal opening (as viewed in FIGURE 8) between a horizontal line tangent to the lower edge of the finger 52 and a horizontal line intersecting the upper corner of the tab 48 has a height that is less than the vertical height of the latching tab 43 which is distance between two horizontal lines defined by the upper and lower corners of tab 43 when in the dotted line position shown in FIGURE 8. With this arrangement, as the latching tab 43 clears the end of the finger 52, it will then hit the tab 48 and will remain in engagement with the tab 48 as the door 14 is pushed to its innermost position wherein the upper edge of the door frame 15 hits the ledge 21 of the fixture frame 19.

FIGURE 9 shows the latching tab 43 in' engagement with the tab 48 and with the door at its innermost position. In FIGURE 10, the door is permitted to move downwardly, and, in so doing, the latching tab 43 moves between the tab 48 and the inner curved camming surface 51. Since the vertical distance (as viewed in FIG- URE 8) between the upper corner of the tab 48 and the curved surface 51 is greater than the height of the latching tab 43, the latter will pass freely about the curved surface 51 until it engages the stop 53 and the door will then be latched in the closed position. To open the door, the door need merely be pushed inwardly as shown in FIGURE 11 until the latching tab 43 moves below the stop 53. This will permit the arm 24 to move to a center position as shown in FIGURE 8 with the latching tab to the left of the stop 53'. Then, as the door is released, the latching tab 43 rides upwardly on the surface 50 and permits the door to swing open.

While only one embodiment of this invention has been illustrated and described, it is apparent that alterations, modifications and changes may be made without departing from the true scope and spirit thereof as defined by the appended claims.

What is claimed is:

1. A releasable latch for a closure member hinged to a supporting member and movable to open and closed positions comprising an operating arm pivotally carried by one member and having a latching element on one end thereof, spring means connected to said arm to yieldably maintain it in a predetermined position, a cooperating latching cam carried by the other member, said latching cam having a pair of angularly disposed camming surfaces each intersecting and inclined in the same direction relative to a line defined by the pivotal attachment of said arm to said one member and said latching element when the arm is in said predetermined position, said surfaces diverging outwardly and downwardly relative to said arm, said latching cam further having a concave camming surface joining the outer ends of said pair of surfaces, a stop carried by said latching cam at the intersection of said concave surface with one of said pair of surfaces farthest from said latching element, and a second stop spaced downwardly from said concave surface to engage said latching element during movement of said members one toward the other, said latching element leaving said second stop and engaging the first stop upon reversal of the relative movement of said members, said arm is being carried by a bracket secured to said one member, said bracket having a slotted opening therein pivotally retaining said arm and said spring means surrounding said arm and engaging the latter on one end and said bracket on the other end.

2. A releasable latch according to claim 1 wherein said one member includes a bracket of resilient material releasably secured to said one member, said bracket including an arm receiving slot therein and said spring means comprising a coiled spring surrounding said arm and reacting between said arm and said bracket.

3. A releasable latch for a closure member hinged to a supporting member and movable to open and closed positions comprising a U-shaped bracket of resilient material, one of said members including a bracket receiving opening therein, said bracket having means extending outwardly from the end of the legs thereof and retained in engagement with the slot edges by the resilient action of said bracket, an operating arm having a latching element on the end thereof, said bracket including an arm receiving opening therein, spring means surrounding said arm and reacting between said arm and said bracket to hold the arm in engagement with the bracket and in a predetermined position relative to the bracket, and a latching cam carried by said other member for cooperation with said latching element to automatically latch the closure when moved to the closed position and to release the closure when the latter is moved inwardly of the supporting memher and then released.

4. A releasable latch according to claim 3 wherein said arm includes a shank of substantially uniform width, a portion of reduced section spaced from the end of said shank and a second portion of reduced section with said second portion adjoining the first portion and having smaller dimensions than said first portion, and wherein said bracket opening is formed of a pair of spaced parallel slots joined by a central intermediate slot, one of said pair of slots having a size and configuration corresponding to the size and configuration of said shank and slidably receiving said shank, the other of said pair of slots being smaller than said one slot and having a size and configuration corresponding to the size and configuration of said first reduced portion for slidably receiving the last said portion, and said intermediate slot having a size and configuration that will only accept said second reduced portion.

5. A releasable latch for a closure member hinged to a supporting member and movable to open and closed positions comprising a U-shaped bracket of resilient material, one of said members including a bracket receiving opening therein, said bracket having means extending outwardly from the end of the legs thereof and retained in engagement with the slot edges by the resilient action of said bracket, an operating arm having a latching element on the end thereof, said bracket including an arm receiving opening therein, spring means surrounding said arm and reacting between said arm and said bracket to hold the arm in engagement with the bracket and in a predetermined position relative to the bracket, and a cooperating latching cam carried by the other member, said latching cam having a pair of angularly disposed camming surfaces each intersecting and inclined in the same direction relative to a line defined by the pivotal attachment of said arm to said one member and said latching element when the arm is in said predetermined position, said surfaces diverging outwardly from said arm, said latching cam further having a concave camming surface joining the outer ends of said pair of surfaces, 2. stop carried by said latching cam at the intersection of said concave surface with one of said pair of surfaces farthest from said latching element, and a second stop spaced outwardly from said concave surface to engage said latching element during movement of said members one toward the other, said latching element leaving said second stop and engaging the first stop upon reversal of the relative movement of said members.

6. A releasable latch according to claim 5 wherein said arm includes a shank of substantially uniform width, a portion or" reduced section spaced from the outer end thereof and a second portion of reduced section with said second portion adjoining the first portion and having smaller dimensions than said first portion, and wherein said bracket opening is formed of a pair of spaced parallel slots joined by a central intermediate slot, one of said pair of slots having a size and configuration corresponding to the size and configuration of said shank and slidably receiving said shank, the other of said pair of slots being smaller than said one slot and having a size and configuration corresponding to the size and configuration of said first reduced portion for slidably receiving the last said portion, and said intermediate slot having a size and configuration that will only accept said second reduced portion.

References Cited by the Examiner UNITED STATES PATENTS 1,493,794 5/ 1924 Robertson.

1,509,780 9/ 1924 Robertson.

2,817,554 12/1957 Hasselmark.

2,844,401 7/ 1958 Kaufman.

2,935,353 5/1960 Loeb 292 251.5 3,053,560 9/1962 Flanigen et a1.

3,069,540 12/1962 Jones.

3,156,419 11/1964 Wince 292 122 EDWARD C. ALLEN, Primary Examiner.

RICHARD E. MOORE, Examiner. J. R. MOSES, Assistant Examiner. 

1. A RELEASABLE LATCH FOR A CLOSURE MEMBER HINGED TO A SUPPORTING MEMBER AND MOVABLE TO OPEN AND CLOSED POSITIONS COMPRISING AN OPERATING ARM PIVOTALLY CARRIED BY ONE MEMBER AND HAVING A LATCHING ELEMENT ON ONE END THEREOF, SPRING MEANS CONNECTED TO SAID ARM TO YIELDABLY MAINTAIN IT IN A PREDETERMINED POSITION, A COOPERATING LATCHING CAM CARRIED BY THE OTHER MEMBER, SAID LATCHING CAM HAVING A PAIR OF ANGULARLY DISPOSED CAMMING SURFACES EACH INTERSECTIG SAID INCLINED IN THE SAME DIRECTION RELATIVE TO A LINE DEFINED BY THE PIVOTAL ATTACHMENT OF SAID ARM TO SAID ONE MEMBER AND SAID LATCHING ELEMENT WHEN THE ARM IS IN SAID PREDETERMINED POSITION, SAID SURFACES DIVERGING OUTWARDLY AND DOWNWARDLY RELATIVE TO SAID ARM, SAID LATCHING CAM FURTHER HAVING A CONCAVE CAMMING SURFACE JOINING THE OUTER ENDS OF SAID PAIR OF SURFACES, A STOP CARRIED BY SAID LATCHING CAM AT THE INTERSECTION OF SAID CONCAVE SURFACE WITH ONE OF SAID PAIR OF SURFACES FARTHEST FROM SAID LATCHING ELEMENT, AND A SECOND STOP SPACED DOWNWARDLY FROM SAID CONCAVE SURFACE TO ENGAGED SAID LATCHING ELEMENT DURING MOVEMENT OF SAID MEMBERS ONE TOWARD THE OTHER, SAID LATCHING ELEMENT LEAVING SAID SECOND STOP AND ENGAGING THE FIRST STOP UPON REVERSAL OF THE RELATIVE MOVEMENT OF SAID MEMBERS, SAID ARM IS BEING CARRIED BY A BRACKET SECURED TO SAID ONE MEMBER, SAID BRACKET HAVING A SLOTTED OPENING THEREIN PIVOTALLY RETAINING SAID ARM AND SAID SPRING MEANS SURROUNDING SAID ARM AND ENGAGING THE LATTER ON ONE END AND SAID BRACKET ON THE OTHER END. 